SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63cab3554b23d1e83047b39111ead9d28cdd264f755d3d1a041bafaf1db5316c' 
  AND token = 'DA/PO7GoIG9bcE/XfaPn1ZcwCe2OdHjKVoK9kyypZQA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}